FuzzyEER: Main Characteristics of a Fuzzy Conceptual Modeling Tool

Abstract

In this chapter we present the FuzzyEER Model, which is an extension of the EER Model with fuzzy semantics and notations. The Entity-Relationship Model was introduced by Chen (1976). Since then, numerous modifications and extensions of its modeling capabilities have been suggested. We will mainly use the approach by Elmasri and Navathe (2000) because it is very popular, general, and has an international scope. With regard to the fuzzy attributes, the following aspects will be defined in the FuzzyEER Model: imprecise attributes, fuzzy attributes associated to one or more attributes or with an independent meaning, as well as degrees of fuzzy membership to the model itself. Furthermore, the following concepts will also be defined: fuzzy aggregation, fuzzy entity, weak fuzzy entity, fuzzy relationship, and defined specialization with fuzzy degrees. Fuzzy constraints are very important, and we review them in this chapter as well.